U.S. patent number 5,123,598 [Application Number 07/564,948] was granted by the patent office on 1992-06-23 for portable spreading devices.
This patent grant is currently assigned to The O. M. Scott & Sons Company, Inc.. Invention is credited to James D. Amerine, Steve P. Courtney.
United States Patent |
5,123,598 |
Courtney , et al. |
June 23, 1992 |
**Please see images for:
( Certificate of Correction ) ** |
Portable spreading devices
Abstract
A hand held spreading device is disclosed for broadcast
spreading material via a rotating impeller. The device has an
actuating assemly including an actuating member and a dual spring
arrangement interconnected with the actuating member. One of the
springs causes material to be discharged onto the impeller in
response to movement of the actuating member and prevents damage of
the device resulting from excessive movement of the actuating
member. The second spring biases the actuating member to move to an
idle position in which no material is discharged onto the impeller
and causes the actuating member to return to this idle position
after movement thereof.
Inventors: |
Courtney; Steve P.
(Westerville, OH), Amerine; James D. (Marysville, OH) |
Assignee: |
The O. M. Scott & Sons Company,
Inc. (Marysville, OH)
|
Family
ID: |
24256565 |
Appl.
No.: |
07/564,948 |
Filed: |
August 7, 1990 |
Current U.S.
Class: |
239/686; 222/473;
239/526; 239/683 |
Current CPC
Class: |
A01C
15/02 (20130101); A01C 7/02 (20130101) |
Current International
Class: |
A01C
15/02 (20060101); A01C 7/02 (20060101); A01C
7/00 (20060101); A01C 15/00 (20060101); A01C
017/00 () |
Field of
Search: |
;239/375,379,652,653,683,686,154,526,687 ;222/470,472,473,175
;251/321,326,285 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Kashnikow; Andres
Assistant Examiner: Merritt; Karen B.
Attorney, Agent or Firm: Jones, Day, Reavis & Pogue
Claims
I claim:
1. A hand-held material spreading device comprising:
a housing having a storage chamber and a manually engagable pistol
grip-type handle;
said storage chamber being positioned over an impeller and
including a port for discharging material from said storage chamber
onto said impeller, said impeller being disposed and structured to
rotate and to broadcast said material deposited thereon;
a valve member mounted for reciprocal motion across said port to
regulate the flow of material in response to operation of an
actuating assembly;
said actuating assembly including an actuating member mounted on
the surface of said pistol grip-type handle and a dual spring
arrangement interconnected with said actuating member; and
said dual spring arrangement including a first spring for moving
said valve member in response to movement of said actuating member
to open said port to allow said flow of material and to close said
port to stop such flow of material, said first spring also
preventing damage of said device resulting from excessive movement
of said actuating member and a second spring for biasing said
actuating member to an initial, idle position and for causing said
actuating member to return to said idle position after said
actuating member has been moved.
2. The spreading device of claim 1 wherein said actuating member is
a trigger-like member.
3. The spreading device of claim 1 wherein said first spring is
operatively interconnected with said valve member via a linkage
assembly so that upon movement of said actuating member, said first
spring causes said linkage to pivot and to move said valve
member.
4. The spreading device of claim 3 wherein said linkage assembly
includes a triangular link member having pegs at each of the three
corners of the triangle, one of said pegs providing a fulcrum for
pivotal motion of said link member, a second of said pegs being
structured and dimensioned to engage said actuating assembly and to
cause said link member to pivot about said fulcrum and the third of
said pegs being interconnected with said valve member to cause said
valve to move in response to the pivotal movement of said link.
5. The spreading device of claim 3 wherein said first spring
extends in a first direction from said actuating member and is
structured and dimensioned to interconnect with said linkage and
said second spring extends in a direction generally opposite said
first direction and is structured and dimensioned to contact an
inner wall of said pistol grip-type handle to provide a prestressed
pressure for said biasing and said return of said actuating
member.
6. The spreading device of claim 5 wherein said second spring has a
hooked distal end skewed between about 5.degree. and 25.degree.
relative to its vertical axis and said spring is force fit into
said handle causing said skewed distal end of said spring to
contact said inner wall and to conform to the shape of said inner
wall resulting in a prestressed pressure for said biasing and said
return of said actuating member.
7. The spreading device of claim 1 including a stop member on a
rate adjusting assembly mounted to engage said valve member upon
movement of said valve member a sufficient distance to provide a
preselected extent of opening of said port.
8. The spreading device of claim 7 wherein said stop member on said
rate adjusting assembly is a cam member having a cam stop surface
which is positioned to contact said valve member and stop further
movement thereof.
9. The spreading device of claim 8 wherein said rate adjusting
assembly includes a manually manipulatable rate knob providing a
number of selectable setting positions, said knob being rotatable
to cause rotation of said cam member and to adjust said cam stop
surface to a desired position.
10. The spreading device of claim 1 wherein said actuating member
and said dual spring arrangement including said first and said
second springs are formed as an integral, one piece assembly.
11. The spreading device of claim 1 including a locking mechanism
for locking said actuating member in a position causing said valve
member to be maintained in a position providing a preselected
opening of said port.
12. The spreading device of claim 1 wherein said second spring has
a hooked distal end section for providing a prestressed tension
biasing said actuating member to said idle position.
13. The spreading device of claim 12 wherein said hooked distal end
section is force fit into said handle causing said end section to
generally conform to the shape
14. A hand-held spreading device comprising:
a housing including a storage chamber;
an impeller;
means for discharging material from said storage chamber onto said
impeller for broadcasting said material;
an actuating assembly interconnected with said discharging means
for operating said discharging means;
said actuating assembly including an actuating member and a dual
spring arrangement interconnected with said actuating member;
said dual spring arrangement including a first spring extending
from said actuating member in a first direction and a second spring
extending from said actuating member in a direction generally
opposite said first direction;
said first spring being structured and dimensioned to cause said
discharging means to discharge material in response to movement of
said actuating member and to prevent damage of said device
resulting from excessive movement of said actuating member; and
said second spring being structured and dimensioned to bias said
actuating member to move to an idle position at which said first
spring will not cause said discharging means to discharge material
and for causing said actuating member to return to said idle
position after said actuating member has been moved.
15. The spreading device of claim 14 wherein said actuating member
and said dual spring arrangement including said first and said
second springs are formed as an integral, one piece assembly.
16. The spreading device of claim 14 including a locking means for
locking said actuating member in a position at which said first
spring causes said discharging means to discharge material.
17. The spreading device of claim 14 wherein said first spring is
structured and dimensioned to collapse upon excessive movement of
said actuating means to prevent said damage of said device.
18. The spreading device of claim 14 wherein said second spring is
structured and dimensioned to provide a prestressed pressure on
said actuating member after installation in said device whereby
said actuating member is biased to said idle position and is caused
to return to said idle position after movement.
19. The spreading device of claim 14 including a manually engagable
handle with said actuating assembly being positioned in said handle
and said actuating member being a trigger-like member positioned
and configured for alleviating fatigue of a user's hand during use
of said device.
20. The spreading device of claim 19 wherein said handle is a
pistol grip-type handle.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to portable spreading
devices. More particularly, the invention relates to hand-held,
manually operated spreading devices for use in broadcasting
particulate materials such as granular fertilizers and the
like.
2. Description of Related Art
Various portable, hand-held material spreading or broadcasting
devices have been disclosed heretofore. For example, U.S. Pat. Nos.
3,157,402; 3,226,461 and 4,492,341 show versions of such devices
which employ valve members normally spring biased to a closed
position for shutting off flow of material from a storage chamber
to a broadcasting impeller. In the devices disclosed therein, the
valve member is opened by operation of a manually displaceable
actuating member to enable material to flow from the storage
chamber onto the broadcasting impeller. The actuating member is
positioned for engagement and displacement by a finger, usually a
thumb, of the hand grasping the handle. A crank handle is provided
for manipulation by the user's other hand to cause the impeller to
rotate and broadcast the material deposited thereon. The devices
also include adjustment members which may be set to determine the
degree of opening of the valve member from fully open to some
intermediate position upon operation of the actuating member.
These prior devices have been found to present problems in regard
to their tendency to break as a result of the user subjecting the
operating components of the devices to overstressed conditions by
exerting an excess force on the actuating member in an attempt to
achieve a greater flow of material through the device. For example,
U.S. Pat. No. 4,492,341 attempts to provide a solution to this
problem by installing a stop element adjacent the actuating member
in order to prevent excessive displacement of the actuating member.
Also, the actuating member supporting structure is formed from a
material and is dimensioned to flex without breaking upon forced
movement of the actuating member. However, these proposed
modifications have not fully solved the inherent premature
destruction problems encountered with these prior devices.
Furthermore, these modifications have not totally corrected another
problem in the design of these prior devices. That is, if
sufficient force is applied on the actuating member by a user of
the device, the actuating member may be displaced from its original
set position to an unselected position whereby the valve opening is
reset to provide an undesired material flow rate from the
device.
In addition, as designed these prior devices normally require
constant finger or thumb pressure to be applied to the actuating
member in order to continue dispensing particulate material for
broadcast spreading. Accordingly, a human engineering or ergonomic
problem is presented since these prior devices have not been
configured to satisfactorily accommodate prolonged finger or thumb
engagement with the actuating member. In practice, it has been
found that the finger or thumb which is employed to hold the
actuating member in operative engagement encounters an undesirably
high degree of fatigue as a result of the application of constant
pressure.
Furthermore, it has been found that as the user's finger or thumb
tires through prolonged usage of these prior devices, the finger or
thumb will back off in exerting force on the actuating member and
the extent of valve opening will be impacted thereby resulting in
varying levels of granular material being dispensed or applied to
adjoining sections of a lawn or other such area causing striated or
patchy growth therein. Also, in the construction of these devices,
there is no capability to release the thumb or finger pressure on
the actuating member and to continue broadcasting material from the
devices. Therefore, in the absence of such a locking mechanism,
once the finger or thumb pressure is removed all dispensing of
material will cease whether such action is desired or not.
In other prior devices such as those known as the "Handi-Spred"
Lawn and Garden Spreader of Precision Products, Inc. and "The
Little Bit" Spreader of Global Products, Inc., the products are
constructed to operate without maintaining pressure or force on the
valve actuating and setting mechanism. In such devices, the extent
of opening of the valve member to allow material to flow from the
storage chamber to the broadcasting impeller is preselected by
moving the actuating member into engagement with a locking
mechanism which sets the valve opening at a preselected level.
Thus, in order to shut off material flow with these devices, it is
necessary to physically disengage the actuating member from the
locking mechanism and move it to a position corresponding to a
closed valve condition.
Thus, an inherent problem in the construction of these prior
devices results from their tendency to continue dispensing material
to the impeller even in the event that the impeller ceases to be
rotated to broadcast such material. That is, since there is no
automatic release feature in these so-called "on-off" or delivery
devices, any momentary or extended cessation of operation of the
device requires manual disengagement of the actuating member from
the open or on condition to avoid undesired release of
material.
Further problems have been encountered with these prior art devices
in regard to the necessity to readjust the application rate to a
specified level each time use of the device is resumed after some
stoppage. Furthermore, these "on-off" devices have generally been
found to be cumbersome in construction including more moving parts
than automatic release, spring biased designs. Consequently, a
problem of wear of the additional moving parts is presented by
these devices.
SUMMARY OF THE INVENTION
In response to the above-noted shortcomings of the prior art, the
present invention has been developed. The invention provides a
portable hand-held manually operated device for broadcasting or
spreading granular materials such as fertilizers, herbicides,
pesticides, seeds and the like. The device includes a housing
having a storage chamber affixed to a manually engagable pistol
grip-type handle. The storage chamber is positioned over an
impeller and includes an opening or port for gravitational flow of
material from the chamber onto the impeller. The impeller is
horizontally disposed and is structured to rotate in order to
broadcast or spread material deposited thereon in a direction
lateral to and longitudinally forward of the device.
A valve member is mounted for reciprocal motion across the port to
regulate the flow of material in response to the operation of an
actuating assembly. The actuating assembly includes an actuating
member, preferably a trigger-like member, mounted on the surface of
the pistol grip-type handle and a dual spring arrangement
interconnected with the actuating member.
A first spring of the dual spring arrangement is operatively
interconnected with the valve member via a linkage in a manner such
that upon depression of the actuating member, this first spring
causes the valve member to move and open the port. As the actuating
member is further depressed, the valve continues to move under the
influence of the first spring and linkage until the valve member
contacts a stop member on a rate adjusting assembly which is
mounted on the handle in position to engage the valve member when
it has moved a sufficient distance to provide a preselected extent
of opening of the port.
Since the stop member prohibits further movement of the valve
member beyond the selected point, continued depression of the
actuating member could result in damage of the internal operating
componentry of the device as has been the case in the above-noted
prior devices. However, in the present construction, any further
depression of the actuating member past the point at which the
valve member contacts the stop member will result in an overtravel
condition of the first spring of the dual spring arrangement
wherein the spring collapses and can no longer cause movement of
the valve member via the linkage. Accordingly, further depression
of the actuating member will not cause damage to the internal
components of the device since no further stress is applied thereto
by virtue of such action.
The second spring of the dual spring arrangement is prestressed or
tensioned so as to constantly apply a force on the actuating member
biasing the member to its initial idle or undepressed position.
Thus, the second spring of the dual spring arrangement performs a
return function so that upon release of the application of force
depressing the actuating member at any stage, the second spring
causes the valve member to return to its initial closed position
via movement of the actuating member to its undepressed state under
the influence of the second spring and such movement of the
actuating member causes the first spring and the linkage to act on
the valve member.
In a modification of the invention, a mechanism is provided for
locking the actuating member in an engaged or depressed state. This
mechanism enables the flow of material from the storage chamber to
the impeller to be maintained at a predetermined, selected rate
without applying continuous pressure on the actuating trigger.
A general object of the invention is to provide an improved
portable, hand-held spreading device.
Another object of this invention is to provide a hand-held,
manually operated spreading device in which the actuating member
can be subjected to a high degree of force by excessive depression
of the actuating member without overstressing or causing breakage
of the operating components of the device. A related object is to
provide such a spreading device in which the actuating member can
be subjected to excessive force without causing displacement of the
preset valve opening to an unselected position resulting in an
undesired material flow rate.
A further object of this invention is to provide an ergonomically
advantageous hand-held, manually operated spreader construction
including a pistol grip-type handle for holding the device with a
trigger-like actuating member for alleviating fatigue of the user's
hand during use of the device and to avoid back off of force
exerted on the actuating member by the user during prolonged use
whereby more constant material flow rates can be maintained.
A still further object is to provide a hand-held manually operated
spreading device having an automatic release feature biasing the
actuating member to its undepressed condition to avoid undesired
release of material upon cessation of operation and readjustment
requirements.
Another object is to provide a hand-held, manually operated
spreading device having fewer moving parts to enable a more
streamlined, long-lasting structure which may be produced
effectively at lower cost and which presents a visually appealing
and aesthetically attractive appearance.
Other objects of the invention, in addition to those set forth
above, will become apparent to one skilled in the art from the
following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a spreading device in accordance
with the present invention;
FIG. 2 is a side elevational view of the device shown in FIG. 1
with a portion of the housing broken-away to illustrate a valve
operating assembly of the device including a trigger-like actuating
member depicted in an initial, undepressed state and a dual spring
arrangement interconnected with the trigger for causing reciprocal
movement of the valve member and for biasing the trigger to the
undepressed state;
FIG. 2A is a fragmentary view of the trigger-like actuating member
and one spring of the dual spring arrangement of FIG. 2 depicting
in detail the interconnection of the spring with an intermediate
linkage;
FIG. 3 is a front elevational view of the device shown in FIG. 1
with a portion of the housing broken away to illustrate an impeller
operating assembly of the device including a gear arrangement;
FIG. 4 is a top plan view of the device shown in FIG. 1;
FIG. 5 is a side elevational view similar to that shown in FIG. 2
with the trigger-like actuating member depressed to an extent
causing the valve member to have moved into contact with a stop
member of a rate adjusting assembly;
FIG. 6 is another side elevation similar to that shown in FIGS. 2
and 5 with the trigger-like actuating member depressed to a further
extent than illustrated in FIG. 5;
FIG. 7 is an enlarged fragmentary view showing an alternate
embodiment of the trigger-like actuating member of a device in
accordance with the present invention including a mechanism for
locking the actuating member in position with the locking mechanism
in a disengaged position; and
FIG. 8 is an enlarged fragmentary view similar to that shown in
FIG. 7 illustrating the locking mechanism of the trigger-like
actuating member in an engaged position locking the member in an
engaged or depressed state.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a spreading device 10 of the present invention having
a housing 12 including a manually engagable pistol grip-like handle
14 and a storage chamber or hopper 16 for accommodating flowable
granular or particulate materials such as fertilizers, herbicides
and other pesticides, seeds and the like. The storage chamber 16
has an open top end 18 to receive the material and a bottom wall 20
and peripheral side walls 22 are provided in the housing 12 to
enclose the chamber 16. The housing 12 also includes an internal
side wall 24 having an upper or first section 26 extending
downwardly essentially at a right angle to an outer edge surface 28
at the open top end 18 of chamber 16 and a lower or second section
30 extending slopingly downward from the bottom of the first
section 26. This internal wall 24 separates the storage chamber 16
from a recess area 32 formed in handle 14 so that the operating
components of the device 10 which are housed in the handle 14 are
shielded from the material stored in chamber 16.
As best illustrated in FIGS. 2 and 5-6, a port or opening 34 is
provided between the bottom of the sloping second section 30 of
wall 24 and the adjacent bottom wall 20 of storage chamber 16 to
enable gravitational flow of material through a chute 36 having
front and rear walls 38 and 40, respectively, leading downwardly
and outwardly from port 34 in storage chamber 16 onto an
essentially horizontally rotating impeller 42 positioned beneath
the storage chamber 16.
The mechanism for operation of impeller 42 is best illustrated in
FIGS. 3 and 4 wherein impeller shaft 44 is shown journaled in
bearings 46 and 48 respectively provided in spaced transversely
extending housing walls 50 and 52. The shaft 44 is keyed to the hub
or impeller 42 so that the impeller rotates with the shaft 44. An
agitator number 54 is secured to the upper end of the shaft 44
which protrudes into storage chamber 16 through hole 56 in bottom
wall 20 of the chamber 16. The agitator 54 rotates with the shaft
44 to stir the material in the chamber 16 and to facilitate the
flow of material from the storage chamber 16 through port 34 and
into chute 36.
Shaft 44 is driven by a gear and crank assembly including a crank
knob 60, a crank 62, a crank shaft 64, a bevel gear 66, a pinion
gear 68 and a drive gear 70 which is affixed to the shaft 44. In
operation, the crank 62 is rotated by a user of device 10 in either
a clockwise or counterclockwise direction by application of force
on crank knob 60. The crank knob 60 is freely rotatable on the
crank 62 and transfers force from the hand of the user to the
crank. The crank 62 is operatively interconnected with bevel gear
66 via crank shaft 64 so that rotational force applied to the crank
62 is transferred to the bevel gear 66 which rotates in the same
direction as the crank 62. The bevel gear 66 meshes with pinion
gear 68 causing the rotational force of bevel gear 66 to be
transferred to pinion gear 68 and causing gear 68 to rotate. The
pinion gear 68 then transfers this rotational force to the drive
gear 70 and the affixed shaft 44 in a manner such that the shaft 44
rotates in a direction opposite the rotational direction of pinion
gear 68. Thus, rotation of crank 62 on handle 14 results in
rotation of shaft 44 which in turn causes impeller 42 which is
connected to shaft 44 to rotate and to broadcast spread material
deposited thereon in a pattern lateral to and longitudinally
forward of the device 10.
Valve member or shut-off slide plate 72 is mounted for sliding,
reciprocating motion in a plane generally parallel to the sloping
plane of second section 30 of wall 24 so that an end valve member
74 moves across port 34 to regulate the opening of the port and,
consequently, the flow of material through the port 34. In
assembly, the valve member 72 is operatively supported adjacent end
section 74 by the rear wall member 40 of chute 36.
The valve member 72 is normally biased to a closed position with
the end section 74 covering the port 34 via operation of trigger
assembly 76 housed in recess area 32 in handle 14. As best
illustrated in FIGS. 2 and 5-6, trigger assembly 76 includes a
trigger-like actuating member 78 and a dual spring arrangement
generally designated 80 including a first spring 82 and a second
spring 84.
Actuating member 78 is mounted on the surface of the pistol
grip-like handle 14 in a manner such that in normal use of the
device 10, the user can comfortably and efficaciously grasp the
device by the handle 14 with either hand and the actuating trigger
78 will be readily accessible to the index finger of the user's
hand to achieve desirable ergonomic and human engineering
attributes in operating the device 10.
Within recess 32 in handle 14, spring 82 extends generally upwardly
from actuating member 78 while spring 84 extends generally
downwardly therefrom. As will be described hereinafter, spring 82
is structured and dimensioned to cause valve 72 to move in response
to movement of actuating member 78 and, also, to compensate for any
overtravel conditions of the actuating member 78 as it is depressed
into recess 32 in handle 14 whereby breakage and overstressing of
the operating components of the device 10 is prevented. As best
illustrated in FIG. 2A, spring 82 is generally configured in a
C-shape and has a looped extension section 83 formed at its distal
end.
Spring 84 is structured and dimensioned to bias actuating member 78
to an undepressed, non-operative condition and further functions as
a return means for the actuating member 78, preferably, applying a
return pressure or force in the range of about 1-3 lbs. on the
actuating member 78. As illustrated spring 84 is shaped to
generally conform to the shape of the lower portion of the handle
14 and includes a hooked distal end section 85 which prior to
installation in the handle 14 is skewed outwardly between about
5.degree. and 25.degree., preferably 5.degree. to 10.degree.,
relative to its vertical axis. Thus, upon installation, the hooked
distal end section 85 of spring 84 is force fit into the handle 14
causing the end section 85 to generally conform to the shape of the
handle and to provide a prestressed tension or pressure which is
transmitted to the actuating member 78 by spring 84 as a biasing or
return pressure.
As illustrated, springs 82 and 84 are formed as an integral one
piece assembly with actuating member 78. However, if desired, these
members may be produced separately or with only partial integration
of components. Furthermore, the constituent components of the
assembly 76 are normally formed from suitable plastic materials
although metal parts may be employed, if desired.
Movement of valve member 72 to a preselected intermediate or full
flow opening position as set by a rate determining cam assembly 86
to be described hereinafter, is controlled by operatively
connecting trigger assembly 76 with the valve member 72 via linkage
assembly 88. Linkage 88 includes a triangular link member 90 having
pegs or pins 92, 94 and 96 arranged respectively, at each of the
three corners of the triangle. Peg 92 is structured and dimensioned
to mateably cooperate with a notch or groove 98 formed in a
projection or tang 100 extending from the surface of valve member
72. As best illustrated in FIG. 2A, peg 94 is structured and
dimensioned to mateably engage with the looped extension 83 of
spring 82 and peg 96 is structured and dimensioned to pivotally
engage with a notched or grooved surface 104 formed in a ledge or
shelf portion 97 of housing 12 which projects inwardly into recess
32 in handle 14.
As illustrated, the rate determining cam assembly 86 has a manually
manipulatable rate knob or dial 106 providing a number of
selectable setting positions, each representing a particular
selected flow rate of material from the storage chamber 16. The
assembly 86 further includes a stem 108 extending from the knob 106
and a cam member 110 having an inwardly and downwardly projecting
cam stop surface 112 positioned thereon. The assembly 86 is
rotatably mounted on an upwardly projecting surface 114 of handle
14 with the knob 106 positioned externally of the surface 114 and
the stem 108 extends through a hole 116 formed in surface 114 to
engage and interconnect with the cam member 110 positioned in
recess 32 in handle 14. Thus, rotation of the knob 106 results in a
coextensive rotation of the cam member 110 whereby the cam stop
surface 112 is adjusted to alter the extent of movement of valve
member 72 and the resulting flow of material through port 34 in
storage chamber 16 in a manner to be described hereinafter.
In operation, as the user of the spreading device 10 begins to
depress the trigger-like actuating member 78, spring 82 of dual
spring arrangement 80 begins to act on linkage assembly 88 via
engagement of the looped terminal extension 83 of spring 82 with
peg 94 on link member 90. This action causes link 90 to begin to
pivot in a counterclockwise direction, illustrated by arrows in
FIGS. 5 and 6, about a fulcrum provided by the pivotal engagement
of peg 96 and notched surface 104 on handle 14 in order to begin to
move valve member or shut-off slide plate 72 upwardly as a result
of the transfer of the counterclockwise pivoting movement of link
90 to valve 72 via engagement of peg 92 in notch 98 in valve
projection 100. The upward movement of valve member 72 continues as
the trigger-like actuating member 78 continues to be depressed and
until valve member 72 abuttingly engages cam stop surface 112 on
cam member 110 of cam assembly 86 which is preset by operation of
rate knob 106. This upward movement of valve member or shut-off
slide plate 72 causes port 34 in storage chamber 16 to open so that
the particulate material in the chamber 16 is channeled out of
chute 36 and deposited onto impeller 42 by gravitational flow from
which it is broadcast or spread in a lateral and longitudinally
forward direction.
As the user of the device 10 continues applying force by depressing
the trigger-like actuating member 78 after the valve member 72 has
contacted and engaged the cam stop 112 as best illustrated in FIG.
6, the overtravel spring 82 of the dual spring arrangement 80
interconnected to actuating member 78 collapses which enables
further depression of the trigger 78 to its most extreme extent of
depression without causing an additional movement of the valve
member and without causing any damage or overstressing of any of
the operating components of the device 10 such as the pegs 92, 94,
96 on link 90 of linkage 88; the projection 100 on valve member or
shut-off slide plate 72, or the notched surface 104 of handle
14.
In regard to the operation of the return spring 84 of the dual
spring arrangement 80, this spring 84 is prestressed or tensioned
to apply a constant force on the trigger actuating member 78
biasing the trigger 78 to an undepressed or idle condition.
Furthermore, as the user of the device 10 applies depressive
pressure on the trigger 78, additional tension is exerted on the
spring 84 via the hooked distal end section 85 of the spring 84 in
contact with the pistol grip-like handle 14 which causes an upper
section 118 of the spring 84 adjacent the trigger 78 to bow and to
further promote return of the trigger-like actuating member 78 to
its initial, undepressed condition.
A modification of the spreading device 10 of this invention is
shown in FIGS. 7 and 8 where a locking mechanism generally
designated 120 is provided to lock actuating member 78 in an
engaged, depressed position enabling maintenance of the valve
opening at a desired level without requiring continuous application
of pressure on the trigger 78. The locking mechanism 120 includes a
leaf spring arm member 122 mounted within recess 32 in handle 14
adjacent trigger-like actuating member 78. Arm 122 projects
outwardly from the handle 14 to a terminal end 124 having a locking
pawl 126 formed thereon with a catch member or tang 128 at its
distal end. As shown in FIG. 7, catch 128 projects upwardly from
pawl 126 so as to abuttingly engage a lower surface 130 of
actuating member 78 when the device 10 is in an idle condition with
actuating member 78 in an undepressed state.
To lock trigger 78 in its engaged position, the trigger 78 is
depressed into handle 14 until it reaches a preselected engagement
position. In such position, catch 128 clears the corner of a
downwardly projecting detent 132 formed on trigger 78 and the catch
128 is manually adjusted upwardly to cause pressure to be applied
to the leaf spring arm 122 until it seats with the detent 132 and
assumes the locked position illustrated in FIG. 8. As shown, the
catch 128 is in locking contact with detent 132 and remains in such
position after removal of force on the trigger 78 to dispense the
desired amount of granular material onto impeller 42 without any
additional application of force on the trigger 78.
In order to unlock trigger 78, force is applied to the trigger 78
to move it slightly inwardly of the locked position. In this
position, the catch 128 will disengage from the detent 132 and the
trigger 78 will return to its unlocked position under the influence
of spring arm 122 which is loaded when the trigger 78 is moved into
the locked position and is unloaded when the catch 128 is released
from locking contact with detent 132. Thus, the trigger 78 is
returned to the unlocked position.
Although the invention has been described in its preferred forms
with a certain degree of particularity, it is to be understood that
the present disclosure has been made by way of example only.
Numerous changes in the details and construction of the combination
and arrangement of parts will be apparent without departing from
the spirit and scope of the invention, as defined in the appended
claims.
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